SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44dae306cd5fc3434d1133a17cf3dd23cb80dc2bc7b394e64e82c8efe2bf4798' 
  AND token = 'HxoOrDPAnsajxUBbVs7i2ULIYX6oGKYUEnHEk+OAnT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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