SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0d290bababe855469deb142c4130b76b962597b7c3a7682f9f3137c367cc083' 
  AND token = 'ryVkGwaFSDAfT5iupZm5fofzEmSUhUcZyGJtifvy7yY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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