SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ef3057b71775451cb025034ad6b9ba554a31ec4070cdd74f219bd126f1154ad' 
  AND token = 'g4jtfFI1VFv9W9NleNZi0ZoFUn9+Ijj0UbzLWqO7PG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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