SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72b7b793a99fcdb19308cd0d570ac08185c278e570fb727bd33a8ac771b9fb8e' 
  AND token = 'pdCWD9osbEw70kb3Sdi2gmKj8MmPasgVgNggUn+nngg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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