SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49659d59056b8d992b45d6c3f44b2061708abb48cafeb1c93189fcc3e5c71d4c' 
  AND token = 'scKrypGjgLivlnHeW7rTPUUj+Zpq5h0uLMYVkver3CU=' 
  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"
    }
  }
}