SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f4f4b305432bef6ca4a2aa9327a6afaf6495bff919ccbe4db93bf7191b29d2' 
  AND token = '+IxBq28lK83NEmo1yekR6JnDOETO8EerqHnnbLTooLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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