SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a825b8074fb73bea7013a23402d9ef6ce23c77d824a00294d658e0d623d145e7' 
  AND token = '8/4atrXs3g56MKNzGKYpHx4lYXhgBUGSmn/Gw7SFAJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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