SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c017ddc246b79e4e1a70b43e539dc12e5201850f3a7059808e0705c346bcdb1a' 
  AND token = 'uYO4hpK4GMagIERzUcarPf98xIdY6fdNi9DOkzBVyP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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