SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2de3a715bfbd14a182d7b14ade05c692f1bde5683a8602d938e2ffb129cd3eca' 
  AND token = 'R8oDxhhikDqVHETxooEV45PuOnNZPUUaj0inV3GtkQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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