SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d14704aa8fd75a4ba2f93d44c7479177a7f6d068305e58b8c220fc8f6566f92' 
  AND token = '+ijdZHZ72ZEh253jE/crfNl8aPPUba9GXNUaCkPgAY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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