SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aee1d06cce46d7a7fabad4a13e4785a5d4332df8b570e312479f82dad6ad1bdf' 
  AND token = '86bP1dCGRm17HayJXxmLYdqqqO7KVif//KmkLMWzSCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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