SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f97eb1621c103d2be5406818658cc1384a4b9bccbdfe86324d384173920e7f' 
  AND token = 'si1CHyUQ/6JGE4DfnWzYAeityHicO4jfH8kTNKI7Cg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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