SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5a28a19eacee2d672b4324045dfef9811a094db1ae6ce72642c231623895c71' 
  AND token = 'hPWXNXIRBx+g4bSnVAxm7uVUlqKiZnmlPwqeWB7puck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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