SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baaa361011d1385373e3c561667e773f5b049106599b23bfa5b3311a609d859b' 
  AND token = 'WahOvUEuQ16WKgpSROLOtwdsUbBmDWcGhh6ldvmukVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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