SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97f672796d4d116fa7e6670399ca3fd4c1711bfe8473f0774310498fa27a28c9' 
  AND token = 'LTeRguTyLok8jVtEmvWnme5buA6OhXKX6fK9GyaOHz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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