SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c53b5efe37edcad6f62371224a2645d84e3ca9d129318c50f22f11b8b300078' 
  AND token = 'hRBAinGCxgV+8pqMltUAQsU7iPQED+FZVsju7XhoEJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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