SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45062a21c4bb88ecd6c1d1c50362a1183eedb97109708fccffafb4a36b737b4f' 
  AND token = '++f4UHhTRdioBsNRDWJV/XqTTsYYgxpF3Jqz7uTJ5h8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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