SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c4b7c11060068fa5d5b515378f18a755fb9f362319b7fca07924630c99b677d' 
  AND token = 'tLnX884K8sfKecdcVQSuCp5QVRsaDuolaYEltA6jR7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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