SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c85cce122e22f4e304887d384b855a3428c3c7be8a0cadc98451dad1e4dae567' 
  AND token = 'UOBtIMuHpCwwGqVct2Glgh0/xwrC8KZcUA0Tfkzq5Ps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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