SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8cee5a9e32d931f3a108b851324ea4c5ff67a64f4016a48b8d5a148ff2daf623' 
  AND token = 'LOm9yznMtEFYSvxvVvDZ7mdomwchy18tsEpSHijvFII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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