SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46ca80430cda8baaf8781dd6025a6e4fe21b72856f8352635b393d790031d9fd' 
  AND token = 'FBLl9vWRgxTSVJkCbv2QwyadIiCaoAZs8bGJ4vUE6oA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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