SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b00d1450c8d6e2d3f715325947ed6d9eaff42656ca135f05d3e6bd0f0de540d' 
  AND token = 'tBEBbmCTAC3LuEVs8F5B/gDrVL+6EwtJxLeFBWbKeoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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