SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b1be0ca2ea8b2c1204d9fed233541727f9bd40123dc2766d220c97220c6459f' 
  AND token = 'thhoRm+LS/XqzuZU5SedMHGOFuSMp7XhBdgX9nWgqRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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