SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46faa157deee06d169b5843b59a7812149b8c5d3f4f157858f4a60b824fa4e0d' 
  AND token = 'Ke8wIARNSsQvX2HB+7/amVuBgSPPOPVcjzcFhrjuqlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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