SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '814a206c0fba79dfe6d0d59c08b8a68e4fe74d927f51ce1f54b86f0192dbe3ab' 
  AND token = 'zNqcEa7VoBAJwGzkDwgIwrh9XvEsEpfQQi2/7j5qh9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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