SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f3968fec47db0cb8cd9cbba59beb0b6e9e6c62d68b5f678def711fc06f8bceb' 
  AND token = 'UOu+ASazqrvdSZgfm8v+0Cb2UtLwoNXSvgaw2/3zSzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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