SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5386182c521c512b0cde046b91333a39955361ca108b29be0c0ce6fba58530f' 
  AND token = 'qxIlIHqP38XpfKjCjZEfyNwsQ8PNcLveICoV71w1U/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}