SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '097733d653e49cb298890f66554e1395d160371aa628f73bbbf5f62678a3e0aa' 
  AND token = 'vSM0oO/4+5P4/jG3lZdVe3coIUWyAigGVPQ1lDWK98Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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