SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '329377f79629529ac2b36ea06294f6da385a46b6a9b94cbc81e1901969f9e807' 
  AND token = 'F7CEeJoZ7dZ6RgQ2xtli9sTjo+h6Pww0wiL/PqFtBhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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