SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '952212f4788b36270430ef8fca2ea010d53d685aa9e647d6dd7c1b8a7507e6f8' 
  AND token = 'hJKzKiXbh8LliwYUB27k9Phxzo+wyuQTLzSg/np2Ink=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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