SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb89bc43ce3ef4907160cfc0777240b175d895b1b111674d394e7375df588cd1' 
  AND token = 'yhsjyTgI6Wewl9JZ2gBF26RsYFh9TDTzYSMcvDREJ6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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