SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a7b69d369acdc142c9315a6b3d3de58508ce41836d3a281f61831063e0d3631' 
  AND token = 'LlryCwxTfAjqXaz4V3q7YxeUfIfuacjOL7y2YyYdKuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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