SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9ab4e0852f9333ce2f4b5cc3bf046cacb33bffdb4698d12cd3cb165fb874bc3' 
  AND token = '9UktqDO6UEYEpe4pv9XPHdfbkfImf7XA7MDYrpwmqgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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