Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a97403c7a73b041c37a4629fafd7dad66df2e64b1bcd5d50cb7a12575d73a45' 
  AND token = '7mpgUNbMNAmlmqfMzAsjIQSLZeLin84I6ywrEP2Wns4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}