SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae76dedb4a3517ff7ba6709c733eca9dc77084879d88a54674ba521e8f6969c5' 
  AND token = 'zmnj6psDGQIVnVtDuoa90GxBa6U+5KWjTj93X9NWSGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}