SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6dc53ed612b914db0a7f959026652e5b0e3731272df1bfec414b621ccec20c5' 
  AND token = '8y+08onpRYsR84eQviYNfZTov5CTh+5V/27c6Sl6s4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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