SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bfea4f8e6f2151bff9a0c72fe87f65cd2b4c7993f0944ebf15f603fcdab8f2f' 
  AND token = 'JELhXSt2ovAUyeNDYTQ+KGqdI0LzhWE/VrbASWo3iLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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