SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7a6501b545797fd979e1df80c58c27494ebdebe271a3242c98bb3e13b7fb809' 
  AND token = 'k7ywx+ZKLiuKJKi0kNwfOL/J3svCauMZ/w331LHUjbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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