SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71223fea58231248029be856c49a7939fd7e2f5358166618616d22580baa9819' 
  AND token = '1/ZPWp8YcbX6JeogoBG2xsPkaf2d+EVMnNZYfvfz/qA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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