SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e2a2219bb198890d6519a65763d04e162fa356f1846fcdcaea1c58ab60143cf' 
  AND token = 'b5/1LRJKWMF+BxyBpZ7nhIEgJC47rLc/kPttMJYeetM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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