SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc9803ff2f34d4a2ee86fc15ff985deb7cc1478a4ed8bb2df588ba1152bef02a' 
  AND token = 'IKh+uOmlKyF3vXD3YCVsUDQpArshnqcLway4ltm7JrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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