SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fea14b24eaf6a62e8ba3340e47150948092e5e14aac5481a68414452d6e961ac' 
  AND token = '3yS74pafOSzcIoy3zqSF4eJCzntsJVRiXDBOQVF/dnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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