SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c9ac96e93090ac5e75bf764231a7a895e1a2dc93567a4b12e79504f616dd80' 
  AND token = 'Bsy/4hL9an3wrWpKhYgBZ5+mqwXBs/4H2YhEDvCgsvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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