SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c4627533fca1799f2fd46a15f025c84dc7bf4cfca049343375279a47433ce83' 
  AND token = 'Uqp9khXotqrho4Xo0aw0Vwj8ilba3EUkOLZyQN3zXl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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