SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '90e4683e5fb2e3f6f57e59d644e294a168e45b17a71f50cbe90c3ba5bc5a3291' 
  AND token = 'b1h1O0Pe5zVkUbdDMqnw+xBWvK2gV6WelZ3TNYo2Pdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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