SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c670deba97d695dd8b6d181bee062ce027a35673fb0a7f049ff5fe3b79e24e8f' 
  AND token = 'I+YFTOJXuO5d/qAY8Ep+uwb39XPmggYic2iyJSMPov8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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