SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a585670096869a1970da1acb91083f7cefa84b17af600270520a7fec696c52c' 
  AND token = 'AQqAJy3lwcolNFwGWWh9OUmnMVlXtx4iOnXi1l1tIQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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