SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da319bc52f6483f6a682301fc8fdf6a3029659bf40fde15c39dc8876a93b4e24' 
  AND token = 'x5qfDTSBZ/DfCoxtNw8PozC5KN6xCmrsbd0lbhNsVak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}