SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd803d099f6a997765ba16ba1fab5991dcd3a12f4c380d32c9039a93c299f53e' 
  AND token = 'OECICz4AYt+iqI4j7OWiYkycUghJ78fag/L7XgfxxZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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