SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7aa2f6cb896fdd92524e69a589bad7cf5f0ebec31b668ef024392db4994b9e3e' 
  AND token = 'mok7VfTSeEI/JgQxBDgHUs7glhzNlnC5w0AVRzPCRcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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