SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '424bbeeab65745eb2c31b154f19ddb742e9279da13241bccda6caac3cfc0d5b7' 
  AND token = '3M4tDxQxsXJ4uiQgRd6COIXDxxV105p/9ilMXVuGUeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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