SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d1d944c92b19b2e9b92adbf51399914aac06a287caa53fb722109808d51776' 
  AND token = 'iqJ6hiCPEAh8YltgFnO3kJgEWh96vUPksg1ZjOKvjJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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