SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fb72483d97bb0416ed8d1daebe8230a879e4db85456c5edccf224391988c793' 
  AND token = 'mIcam/u2wfH5HJ3JnTZNELBJFEQrrRyEdTPWfelO/7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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