SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fcae1df851842d8f9b9b63339fa364dee574de7f57237ea7adb6b15fbea7c28' 
  AND token = 'pMzJHWZqT0ZJgn/QAakU50bZwokeHN3dwYzZfUdrVOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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