SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61c03fd8f5bab4c92802293b39fae4245221305b8ad6226d767df508bf5ccc33' 
  AND token = 'klYoC0wCKXZViJjrXiPbNAjYsRFXIZrr6x7ayZYYWfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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