SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cf3fa8a95e26d6f2a691896a12ec42479e6c7b98320f99191a9daaa62f073b8' 
  AND token = 'd6nyNkT9vyfFYim/fBnReFuCdbd0QTvqVsIeERqqEeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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