SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '459a8a8dc24cef82dbe9ac0187602d2f87b9a0a7501904c2725df141a2960713' 
  AND token = 'Z3lbMGvpi7A8jST34nsr+VgNJTLCUGyBubPwjlo7ucM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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