SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dfc7e4130a1345cfdfa214a84d820c816e5a4f72241e536e6c78e38628060117' 
  AND token = 'TyKTduAgFSxQFp3GO1KuT42cfolmYPvvohzSTqWuVB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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