SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '045499b3b62e4bdf4f2b1c05ff0f057a565e07cef4220f6bd8991efdb31fe2d1' 
  AND token = 'JovEbZKxlw1/JTRXk9TKdJPOE48jA4joLbj5b1ZBimQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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