SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0474d699c4f87e5bbb2319829f02d7bd8936eb16a710f9e801806fa42bd00bd' 
  AND token = 'iJjYj4GxTd7C7vccu32OLkK6WaXRBzUImcBCU+5sV6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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