SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '489102e79e2a268da5151f65ea8c5a37c7badcdaab39dedf2d9088de084274ba' 
  AND token = 'FtCHmPHQJMwSWQkx1Wu41VDlo0lL4y4xeFquOMSz+3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}