SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8b844f8ffcef5c222e6dd88ea63d3e5dc1cc37a4703061dfca7669c2fa8156a' 
  AND token = 'qMbG+AzjWkRxZ5FZ/Lpa+6n/Lqpq9ZRYr6Upupq0hKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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