SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f832f15d41f83311c3568d9ecb386a23103046ebc6238bdef1e12f2667cfd1e7' 
  AND token = 'NGSs9EC2gH4GQw/q7HuVoq2jXb71JfpnHcc2sPvQ6BA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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