SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40bc38820196b8e5975c65c0abcd9e269defee0042fbb82a56914d5ce3237124' 
  AND token = 'cDW9ApeXmFur0fcbHLag314Kt+hSbssG4rU6t7tgtVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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