SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d6f3217c37e34fd1ba74edd6128778962556735764a638221d64b5844db7b54' 
  AND token = 'Qq4miLJWA1BzknZwRq9j3h12GTcvE8FBA3u+yodvIx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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