SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe04be6a59ad2d25c15260586238f7a82f32a6be3eb94d89c06f8eadacf876f6' 
  AND token = 'KIRXOJz4BgbgojwW56SnYVKGUOyKBKsfKlNh/+mFCoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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