SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '585fa133c42889386768a37618a9ddddd6c20469ba8b4bee30cb177b25e0e07b' 
  AND token = 'zXhwsmyILkDMcPGu8vf27UZrGxSZL+sEBIsnQDZIJMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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