SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28d9c27421057db1feb85f875bd6b13781840c97eacc6fad53a46d9ed49288c2' 
  AND token = 'rSwGNudvcDzvdVle0Xf+JL2wLmyAu2WV+lOPZrxtQuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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