SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b758dc865293376010ccd2e48b1b39989e9facef30b12d6985fc0beff380d470' 
  AND token = '4N7Gd2lW3VyRmYdU9F+QgD2sqFqPF8ncfM4MU350vt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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