SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6209b692ba09275e744fb3bc1e84713eaf1fcf2b35698ca3c9679e5df2719ebc' 
  AND token = '3ln13sCzwquL6lJKYTXpIQOXlRTQnvHiOKp0V/loXK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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