SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faee75034855f078ce43ecafa8e12522730516a5fe1208dd875bce02cc5f3647' 
  AND token = 'UrHHtFabW1AXu2Ti3d3zwaw0Lr8wXgUVI4Jbi3vDzFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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