SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fb5803129ee0d50b2db4e1a7f5833e33202c2f3ba50f19e9eb2e6981eb22c2af' 
  AND token = 'cPRpTR5x32JXITCmR/HR6ZawWyOqkIgbJiOFHHEwpp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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