SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ab18e045c0fd7e55bd7b9af5c391171e4ed480fcacec8a839cc060affb3a22e' 
  AND token = 'j73qTynQCaMd+uvK/Vk2tQpfB78XRwEqkXW9uyR9dM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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