SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fc3aaa45fab62589ef5a59f6f0d6315edf5e8b78cc83680eb9a2739a60ba848' 
  AND token = 'on0ggR/LIOPZp5E96NlkVk8PTN2Jp9meaYlUAig4y20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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