SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f66f17fc3f70414b5bc610891429dfebd1d8e29d3c69e55b5dc5786df111229' 
  AND token = 'QDeV0t59wEK2W4D2urnh9v+SIiZ9ezeLZqVGGgOO2PU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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