SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '262af9e4e437979d99a6ad1a9cd2e367343201db72abd9ea7611fd25dd28130b' 
  AND token = 'ofHA75XtdlasAwVBm8jza62aSAR6QTKe0ffJyXT8oTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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