SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b183638cdc33c7a4d92f493b9d8671523fa84323456598f467ac072da00a78d4' 
  AND token = '/EgkGkBuVXgQX1cMRCFjadVLiYGyvtJksKrz4znpqWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}