SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9cf13f3b2a783c365d612cc3169cf5919b2c4bc1eb0fc4f2ae173f4b3db7dd6' 
  AND token = 'ZNIJf02BhncqU3nIn8unnDWlgtiGehDElCA+MUjRoQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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