SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1856c04de3e2da1402ad3e0e67f07bcaf2985e357c86bf86463685a8c790da45' 
  AND token = '26/RuvqmmWw4+KEdy9lmMBLHW5vsg5Vu5prb/TmLUCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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