SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ded2802cd06446cd54c2fdf24a39abe27139d0cf923fc5392bc6c0bbdbfb530' 
  AND token = 's6SA9p+Tcdasw90rzzPKjmpHqW8A7nXhwT92DSK7jvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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