SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a96b6b910ecd45cc4e46e74da2eb2ee9f64e87a679d6b61af622247f11006a2c' 
  AND token = 'yZIin1ciL75pt0rS437PasCydVVVNWw3gcfV0CkerFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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