SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '782c3c15cb8da22ad2146f84c9f2a4ba84592be3471f40daec296466bb20b7ba' 
  AND token = 'MtW8aWVjUKSWr2a/LjUVsGy2C02T2RnyNEZbbwzer1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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