SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bbefc7ce98ed67db333dc938821b3c7de0586158b346fbd2343767797b8e0f6' 
  AND token = 'G03vYIr2PTnALLdoN+PwHL3CpulQ8h1R0A91gVInRVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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