SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41fdf579cff8adf490f00414bec5f5d7ae33930898d5f5544a3f73006ad66b54' 
  AND token = 'k2yEOFDmIsz3Z+QwLUEzsj/ffGkbQ7vDXp3zcdguw9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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