SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e343efb6458f5e31f8832542161333ae2dea8d16142e20cc44b02ca115cf6d6f' 
  AND token = 'FjsZqFHpYIP/ynWcQDGfPD6qAcV8kwDyEPByTA3PSjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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