SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c180b226e892d9721301743db198e0ebffe4d904af988f49912a6744e5263af3' 
  AND token = 'gE+vh06FVmvab7Fl1jcckU/oDlubA5O+pGJr5dbzsHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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