SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a56d8c68ca40b7d9054b3c7632e9f33d49dc8b48f74677137a8748b9c77e8fd' 
  AND token = 'gNURCTTnj5Vq9o3zciDK2QG2DTKhEMNvL2+HoEyJp94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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