SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68d84c5ca1f05aa828b5133c06a2994369e557c827a086fc4923c8b669afa1d7' 
  AND token = 'RoLSbZL0NnusNIMrfgFJgnPzHChQGKihasTEKoB/sso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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