SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b04973f9eb2719faa1651ef33b11f989e1e25584423c48a99ccddb278db69b' 
  AND token = 'MEu/I1KxyHiZalMcwLkdlzQeTsppe4lvmU+sCp5TSvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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