SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '490b314f056c72cdd305a2f5a13d53728efcb99cd6d618931c0b19e48c7f2384' 
  AND token = 'DYHdtVqu3l8YPop8gpFh1OIKrpg5i0Bv17c30OzS8x8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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