SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfb41cf897341364009e1dad31e4f53f6552e49c8656604846f3d485030e3319' 
  AND token = 'cjT/OX9RPMB2ZD/SxgqH3kAlOoBth0VM1M56bRezTuc=' 
  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"
    }
  }
}