SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd015036c0fbecf2e314b3a2a5cf532db630a5511a90bc3a48340aa9144db9b0f' 
  AND token = 'v581s9cLrJqTDzxbUJ95S2if9pXUlchjg2LwEQWhFBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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