Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9e4e736522f1bfa23291814a3318c3aed6410bedb11650d4865319a3608250cf' 
  AND token = 'rz8K+6tsTKEinqyp2WdffCJJvong042bEHfbtwTzKeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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