SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b00cea4e1358a9012aae19d62605fc57081e287ae543d8714f794970f48ccee3' 
  AND token = '0IYTDGtc09slTIVHpjkvhf+Ww2brluWVQtIXtv9wKhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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