SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16b405d361545284a612685653209d2bb4fb4c2b21422f8df09ac518867c7902' 
  AND token = 'gmDXHSP2hxOJB2kKUKkSd5d8878ruLd6GVjV+v7HObI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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