SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9940c9ddf10bb87f3711334e91569d34ba477f5a372c270a0703f97ca2f6745' 
  AND token = 'gzDGlgs3vAFv2dnnNDs/BxRUO9zBZUXhgL2mqX8P/Ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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