SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '879b54d00404c1842175d7602125db5c38e462dd6df5efb3a49c055d9e552b90' 
  AND token = 'VM+Sz3zqPrXw57/P3bZCmkGYSeRWHoxeU/lsw+bganU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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