SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2662713f7c61ee0a199641ab9ec07fba8db699f3251b55ebcf6c3beeae3b70af' 
  AND token = 'kPwBgvc+XN4HRpSn7mFOM3HmzpfPCv9Q0xUpV6vxgws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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