SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4c05c1e1fda37fac100f7b686e970d519afd6e86f11226acd1a2cd5d6048b9f' 
  AND token = 'qPqQ0faE+tpbcO0kDtnKHx5fZsmuYp5E7bgFGfM9qmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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