SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1a2a174ca55014cf25792e21e13c359563e135a6252c08af75cf9f600a2fa591' 
  AND token = 'mBhuhdltZsLZndV5Na7uuB36Li6kyDQSUEQxeNG2g1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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