SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41682c025ca2f2559cf2a12b4494e4ef47d2497c600a4ab24eb8348ff43ef35e' 
  AND token = 'c3jVw1vpfV1dmhhvlp5swcBSxsBrFxbHIvlXxoq17dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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