SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55069890d4c30efda42cf4c589c08cee4b00bb0a07a29ca22affba53dfd6a6ee' 
  AND token = 'qqbfVOYb5eqZehUy6v99lxRlqbxksCPLmVznETdeaxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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