SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f92783822fbe250db4ddfff151a7e8b627ae405097852963ca70ac6b7fc48b9' 
  AND token = '9ao+sTIgJV+6uir/iTxEBGFpzUCDnZaw9YHR9SakoV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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