SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c75b0aaf8326d0ef1443420ad5f0097d60ba3c918b40672bd83650732fe0128' 
  AND token = 'yDPpxPCJxaoTnTpLqC8pF0QnDUQtzwHqD2QuNJLhICc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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