SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe68a773fbbb6ceb22d357f8090f993ec372c2d97f23bbc0d690ba28a3c92223' 
  AND token = 'Y+QSUcwN2C7lqU805mFfbDPCyoqcmpBkIwWzfNVoQHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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