SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cce5303b12a429d6ab738650fb642aa0288df6a2f1a0f6eb9c2fd7922a555016' 
  AND token = 'L/3sWQgonIaZxCDl1DUEWI9/Wk8+35+lV8LKtbgMHuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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