SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ad77e2888f7df012fde6745f6b3e090da4c7e8b74f0bdbf580b8583ffe5073c' 
  AND token = 'qYbybdqaMOugdD2TPoMZE9sg0wMAi4ceMmbmgKtgK8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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