SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e379b2fc2a8e5c9b4a798546dde1ccf83bfa323af2656cf0294daedbbb3365b9' 
  AND token = 'vaht8HzONDBHG2HZHj0OqaKwmgLyh/4qT82sSwsToHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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