SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82e26d44c47221afa5c139059f521ea8ce596e1f767620a22050f00188cfbaa5' 
  AND token = 'oxNyETbzYGtzSBR0V+MSJlFXRzj29eipEfBQ48D0G2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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