SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f86bfdd88c3f181f2741498f669fd5c0c60ec0cc3e56e0fd5d74979cb32ea87' 
  AND token = 'IDN5lhqnoVTuIwvBZKnTKWj3b3k3rZ5XHg1TPB1mMqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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