SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0469f3697c36185d5463fd4af46c9d7cebbce28cc420adfc3f05efe94343e048' 
  AND token = 'lKPxetgAFPRtoU9BXsY+AC/yCdUNgIextYYlyYz+fvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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